The induction and expression of antibodies in ocular fluids and tissues is currently not well documented but it appears that antibodies may be instrumental in mediating immune protection and certain immunopathological events in the eye. Secretory antibodies, which are locally produced and expressed, play roles in enhanced resistance to a variety of infectious agents and may be particularly important in preventing ocular infections. The objective of the proposed study is to determine the mechanisms underlying antibody responses in the eye in order to define the relationship of the ocular immume response to systemic and secretory responses. The current investigation will employ a rat model to study isotype specific antibody induction and expression in ocular fluids (tears, anterior chamber fluid and vitreous humor), other secretions and serum following parenteral, local and remote-site stimulation. Isoelectric focusing will be used to assess the immunochemical relationship of antibodies appearing in ocular fluid, secretions and serum. The somatic cell hybridization system will be employed to develop anti-idiotype reagents to further define the expression of specific antibody populations following immunization. The cellular parameters associated with ocular immune responses will be assessed using histological methods for localizing antibody producing cells. The distribution of isotype bearing cells (unimmunized animals) and antibody producing cells (immunized animals) will be studied using the adoptive transfer system to further define the relationship of the ocular immune system to the mucosal immune system. These studies will provide important information concerning: 1. optimal methods for inducing ocular antibody responses; 2. the immunochemical relationship of antibodies expressed in ocular fluids, secretions and serum; and 3. the precise definition of the cellular events underlying the expression of antibodies in ocular tissues and fluids. The basic information from these studies is an essential step in the development of practical methods for vaccination against ocular infections.